DIN 1587 is the governing dimensional standard for sealing cap nuts. This page sets out the scope of the standard, reproduces the full size table it specifies, and lists the DIN/ISO/ASME cross-references commonly cited in datasheets and drawings.
DIN 1587 — Scope
DIN 1587 is "Hexagon cap nuts (acorn nuts), high type".
Material, property class, surface finish and packaging are governed by separate documents — ISO 898-1 and ISO 898-2 for mechanical property classes, ISO 4042 for electroplated finishes.
Tolerance & Product Grades
DIN 1587 does not divide sealing cap nuts into product grades. Tolerances are given as limits on the individual dimensions in the table.
Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.
Dimensions Specified by DIN 1587
| Thread size | Pitch (mm) | Across flats s (mm) | Across corners e (mm) | Total height m (mm) | Dome diameter (mm) | O-ring seat | Reference standard |
|---|---|---|---|---|---|---|---|
| M5 | 0.8 | 8 | 8.79 | 10 | 8 | 4.5 x 1.5 NBR | DIN 1587 + O-ring |
| M6 | 1.0 | 10 | 11.05 | 12 | 10 | 5.5 x 1.5 NBR | DIN 1587 + O-ring |
| M8 | 1.25 | 13 | 14.38 | 15 | 13 | 7.5 x 2.0 NBR | DIN 1587 + O-ring |
| M10 | 1.5 | 17 | 18.90 | 18 | 17 | 9.5 x 2.0 NBR | DIN 1587 + O-ring |
| M12 | 1.75 | 19 | 21.10 | 22 | 19 | 11.5 x 2.0 NBR | DIN 1587 + O-ring |
| M16 | 2.0 | 24 | 26.75 | 28 | 24 | 15.5 x 2.5 NBR | DIN 1587 + O-ring |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Sealing Cap Nuts page.
Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify DIN 1587
DIN 1587 is still widely used in European mechanical engineering and as a cross-reference on legacy drawings; its ISO equivalent is preferred for new designs.
Custom manufacturing · Made to drawing
Need a nut to this standard in a non-standard size?
Parts built to DIN 1587 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
